DES (dē'ē-ěs')n. Diethylstilbestrol; a synthetic nonsteroidal substance having estrogenic properties and once used to treat menstrual disorders. It is no longer used due to the incidence of certain vaginal cancers in the daughters of women so treated.

(dē'ē-ěs') Short for diethylstilbestrol. A synthetic nonsteroidal substance having estrogenic properties and prescribed between 1938 and 1971 to pregnant women with a history of miscarriage and other problems of pregnancy. It is no longer used due to the incidence of certain vaginal cancers and other disorders in the daughters of women so treated.